<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <form action = "/login" method = "post">
        <p><input type ="text" name ="username"/></p>
        <p><input type ="submit" value ="登录"/></p>
     </form>
</body>
</html>